Determining an Exoplanet

Artist's concept of the star Fomalhaut and the Jupiter-type planet observed by the Hubble Space Telescope. Credit: ESA, NASA, and L. Calcada (ESO for STScI)

Check out this recent report from NASA on an exoplanet named Fomalhaut b, which orbits a 200-million-year-old star [10+08] called Fomalhaut, every 872 years [10+02]:

“A second look at data from NASA’s Hubble Space Telescope is reanimating the claim that the nearby star Fomalhaut hosts a massive exoplanet. The study suggests that the planet, named Fomalhaut b, is a rare and possibly unique object that is completely shrouded by dust.

“In November 2008, Hubble astronomers announced the exoplanet…as the first one ever directly imaged in visible light around another star. The object was imaged just inside a vast ring of debris surrounding but offset from the host star. The planet’s location and mass—no more than three times Jupiter’s [which is 10+27 kilograms]— seemed just right for its gravity to explain the ring’s appearance.

“Recent studies have claimed that this planetary interpretation is incorrect. Based on the object’s apparent motion and the lack of an infrared detection by NASA’s Spitzer Space Telescope, they argue that the object is a short-lived dust cloud unrelated to any planet.

“A new analysis, however, brings the planet conclusion back to life.

“‘Although our results seriously challenge the original discovery paper, they do so in a way that actually makes the object’s interpretation much cleaner and leaves intact the core conclusion, that Fomalhaut b is indeed a massive planet,’ said Thayne Currie, an astronomer formerly at NASA’s Goddard Space Flight Center in Greenbelt, Md., and now at the University of Toronto.

“The discovery study reported that Fomalhaut b’s brightness varied by about a factor of two and cited this as evidence that the planet was accreting gas. Follow-up studies then interpreted this variability as evidence that the object actually was a transient dust cloud instead.

“In the new study, Currie and his team reanalyzed Hubble observations of the star from 2004 and 2006. They easily recovered the planet in observations taken at visible wavelengths near 600 and 800 nanometers [10-07 meters], and made a new detection in violet light near 400 nanometers. In contrast to the earlier research, the team found that the planet remained at constant brightness.”

To read the full story and learn more about the data and scientific analysis on this exoplanet, click here.